The present invention relates to devices for controlling delivery of workpieces and/or workiece containers of substantial size in manufacturing or assembly operations, and more particularly, to an improved material storage and delivery structure and system for storing, delivering, positioning and removing both full and empty workpiece containers to and from assembly or production line work stations as desired.
As is well known, assembly or production line facilities require the delivery to and temporary storage of large volumes of production parts at or near assembly or production line work stations to support worker line operations on a continuous mass production basis. Automotive production or assembly line operations in particular require the delivery of large numbers of parts of substantial size for assembly to automotive or truck vehicles, or subsystems thereof, on a continuous basis. Examples of such parts include engines and engine components, body panel parts, air conditioning assemblies, fuel tanks, and brake assemblies, which are typically stored, moved and delivered to line work stations in structural racks, containers or pallets of substantial volume and mass.
Due to the fact that mass production operations require the continuous delivery of a large number of such parts during any particular workshift, typical assembly line operations require movement, positioning and temporary storage of large numbers of such pallets or containers at the production facility. Substantial floor space is thus often needed for movement and continuous repositioning of both full and empty pallets or containers to facilitate delivery of full pallets to the production line, and removal of empty pallets or parts containers when the production parts contained in such containers have been fully depleted. It is typically necessary to utilize hi-lo or forklift vehicles on a continuous basis to deliver fresh pallets or containers to the assembly line and remove empty containers therefrom throughout a particular working shift to achieve the above-noted objectives.
It is, therefore, desirable to provide a production parts container storage and delivery system which facilitates the delivery of fresh pallets or containers of parts to production line work stations as needed without the necessity of continuous forklift vehicle involvement. It is also desirable to provide such a system which enables empty pallets or containers to be similarly removed from assembly line work stations without continuous supplemental vehicle assistance. It is further desirable to provide such a system which stores and positions full and empty production parts containers as desired, and which facilitates the storage, delivery, positioning and removal of a sufficient number of such containers to obviate the need for supplemental vehicle intervention over an entire workshift. It is also desirable to provide such a system which enables production workers to index individual fresh parts containers to a work station as needed, and which allows for unobstructed and full access to the containers without any hindrance posed by the structure of the delivery system. It is moreover desirable to provide such a system which is of relatively low cost and of a reliable design, and which enables horizontal container movement without the need for complex mechanical transfer systems, so that expenses associated with system controls and maintenance can be reduced. It is furthermore desirable to provide such a system which is adapted to facilitate handling and movement of containers, racks or pallets of diverse types without the need to modify the container movement system.
The present invention is intended to satisfy the above desirable features through the provision of a new and improved container storage and delivery structure and system which is designed in structural modules operative to define a first container storage rack for accumulating and storing pallets or containers of parts as required for a particular workshift. The module structure also defines a second storage rack for storing empty or depleted pallets or containers which accumulate during a particular workshift. The system also defines a full container loading station and an empty container unloading station which can be accessed by a forklift or hi-lo vehicle to deliver full pallets or containers and remove empty containers at the beginning or end of a particular workshift, or otherwise as desired.
The system also includes container indexing and transfer mechanisms for delivering individual containers from the first storage rack to an assembly line work station and positioning them as desired. The transfer mechanism further enables empty containers to be indexed from the work station for delivery to the second storage rack as necessary. The first storage rack is designed to enable positive and controlled gravity flow and accumulation of full pallets or containers from the container loading station toward the transfer mechanism. The second storage rack is similarly designed to provide for such gravity flow of empty containers from the transfer mechanism toward and to the container unloading station. The transfer mechanism, itself, is also provided with means for facilitating the indexing of containers onto and from the transfer mechanism by gravity flow on an individual basis.
In one embodiment of the invention, the first and second storage racks are situated in an over-under configuration, with the first storage rack located above the second storage rack so that full containers are accumulated and stored above empty containers. Moreover, both the loading and unloading stations are disposed at one end of the structure, with the loading station situated above the unloading station. This embodiment of the invention thus conserves maximum floor space and requires minimum forklift vehicle movement for effecting loading and unloading of containers. The transfer mechanism for delivering full containers to the work station and removal of empty containers therefrom is disposed at the opposite end of the structure from the loading and unloading stations.
Other embodiments of the invention include a side-by-side configuration in which the storage racks are disposed laterally of one another. A lateral transfer mechanism indexes and shuttles full containers or pallets from the first rack to the work station, and indexes empty containers or pallets from the work station to the second storage rack. This embodiment of the invention is specifically suited for applications where overhead space in a production facility is restricted or limited. Yet another embodiment of the invention is designed in a closed loop style configuration, and is specifically suited for applications where aisle space is restricted. Further embodiments of the invention include an under-over version, which stores and accumulates full containers along a lower pathway and which stores and accumulates empty containers along an upper pathway, and a side shuttle version, which defines an elongated container flow path extending past a laterally disposed work station and which includes a transverse container transfer system which shuttles containers of parts to a work station for processing and returns containers of processed parts from the work station to the flow path for further movement and/or storage therealong. Each embodiment of the invention is specifically suited for a robotic interface through the use of close tolerance container positioning mechanisms and which enables parts to be obtained and handled from the container with robotic machines. Each embodiment is also suited for use with priority sensors for controlling automatic guided vehicles for loading and unloading containers as required.
The above and other features of the invention will become apparent from a reading of the detailed description of the preferred embodiments, which make reference to the following set of drawings.